Remove zpl_revalidate: fix snapshot rollback

Open files, which aren't present in the snapshot, which is being
roll-backed to, need to disappear from the visible VFS image of
the dataset.

Kernel provides d_drop function to drop invalid entry from
the dcache, but inode can be referenced by dentry multiple dentries.

The introduced zpl_d_drop_aliases function walks and invalidates
all aliases of an inode.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes #9600
Closes #14070

diff --git a/config/kernel-dentry-alias.m4 b/config/kernel-dentry-alias.m4
new file mode 100644 (file)
index 0000000..f0ddb8d
--- /dev/null
+++ b/config/kernel-dentry-alias.m4
@@ -0,0 +1,30 @@
+dnl #
+dnl # 3.18 API change
+dnl # Dentry aliases are in d_u struct dentry member
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_DENTRY_ALIAS_D_U], [
+       ZFS_LINUX_TEST_SRC([dentry_alias_d_u], [
+               #include <linux/fs.h>
+               #include <linux/dcache.h>
+               #include <linux/list.h>
+       ], [
+               struct inode *inode __attribute__ ((unused)) = NULL;
+               struct dentry *dentry __attribute__ ((unused)) = NULL;
+               hlist_for_each_entry(dentry, &inode->i_dentry,
+                   d_u.d_alias) {
+                       d_drop(dentry);
+               }
+       ])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_DENTRY_ALIAS_D_U], [
+       AC_MSG_CHECKING([whether dentry aliases are in d_u member])
+       ZFS_LINUX_TEST_RESULT([dentry_alias_d_u], [
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_DENTRY_D_U_ALIASES, 1,
+                   [dentry aliases are in d_u member])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+])
+

diff --git a/config/kernel.m4 b/config/kernel.m4
index d4d13ddd1d1ae07ce7665cfad9bddc8d42cc82e6..b573881c44000bcaaf5327802de13f3149d23c04 100644 (file)
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -96,6 +96,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
        ZFS_AC_KERNEL_SRC_SETATTR_PREPARE
        ZFS_AC_KERNEL_SRC_INSERT_INODE_LOCKED
        ZFS_AC_KERNEL_SRC_DENTRY
+       ZFS_AC_KERNEL_SRC_DENTRY_ALIAS_D_U
        ZFS_AC_KERNEL_SRC_TRUNCATE_SETSIZE
        ZFS_AC_KERNEL_SRC_SECURITY_INODE
        ZFS_AC_KERNEL_SRC_FST_MOUNT
@@ -217,6 +218,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
        ZFS_AC_KERNEL_SETATTR_PREPARE
        ZFS_AC_KERNEL_INSERT_INODE_LOCKED
        ZFS_AC_KERNEL_DENTRY
+       ZFS_AC_KERNEL_DENTRY_ALIAS_D_U
        ZFS_AC_KERNEL_TRUNCATE_SETSIZE
        ZFS_AC_KERNEL_SECURITY_INODE
        ZFS_AC_KERNEL_FST_MOUNT

diff --git a/include/os/linux/kernel/linux/dcache_compat.h b/include/os/linux/kernel/linux/dcache_compat.h
index 0fbd92458679ac65658ecc477ee3f74e2ff9fcf7..4de1118daafa9a7d40188c5b76438b4dcf8795d0 100644 (file)
--- a/include/os/linux/kernel/linux/dcache_compat.h
+++ b/include/os/linux/kernel/linux/dcache_compat.h
@@ -61,4 +61,25 @@ d_clear_d_op(struct dentry *dentry)
            DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE);
 }
 
+/*
+ * Walk and invalidate all dentry aliases of an inode
+ * unless it's a mountpoint
+ */
+static inline void
+zpl_d_drop_aliases(struct inode *inode)
+{
+       struct dentry *dentry;
+       spin_lock(&inode->i_lock);
+#ifdef HAVE_DENTRY_D_U_ALIASES
+       hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
+#else
+       hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+#endif
+               if (!IS_ROOT(dentry) && !d_mountpoint(dentry) &&
+                   (dentry->d_inode == inode)) {
+                       d_drop(dentry);
+               }
+       }
+       spin_unlock(&inode->i_lock);
+}
 #endif /* _ZFS_DCACHE_H */

diff --git a/include/os/linux/zfs/sys/trace_acl.h b/include/os/linux/zfs/sys/trace_acl.h
index 6a73545fecdadb26273793d0fd0b524c8ae99478..2c734322267af38ce9a7c43fd72564ea2c098bc7 100644 (file)
--- a/include/os/linux/zfs/sys/trace_acl.h
+++ b/include/os/linux/zfs/sys/trace_acl.h
@@ -64,7 +64,6 @@ DECLARE_EVENT_CLASS(zfs_ace_class,
            __field(boolean_t,          z_is_sa)
            __field(boolean_t,          z_is_mapped)
            __field(boolean_t,          z_is_ctldir)
-           __field(boolean_t,          z_is_stale)
 
            __field(uint32_t,           i_uid)
            __field(uint32_t,           i_gid)
@@ -99,7 +98,6 @@ DECLARE_EVENT_CLASS(zfs_ace_class,
            __entry->z_is_sa            = zn->z_is_sa;
            __entry->z_is_mapped        = zn->z_is_mapped;
            __entry->z_is_ctldir        = zn->z_is_ctldir;
-           __entry->z_is_stale         = zn->z_is_stale;
 
            __entry->i_uid              = KUID_TO_SUID(ZTOI(zn)->i_uid);
            __entry->i_gid              = KGID_TO_SGID(ZTOI(zn)->i_gid);
@@ -121,9 +119,8 @@ DECLARE_EVENT_CLASS(zfs_ace_class,
            "zn_prefetch %u blksz %u seq %u "
            "mapcnt %llu size %llu pflags %llu "
            "sync_cnt %u sync_writes_cnt %u async_writes_cnt %u "
-           "mode 0x%x is_sa %d is_mapped %d "
-           "is_ctldir %d is_stale %d inode { "
-           "uid %u gid %u ino %lu nlink %u size %lli "
+           "mode 0x%x is_sa %d is_mapped %d is_ctldir %d "
+           "inode { uid %u gid %u ino %lu nlink %u size %lli "
            "blkbits %u bytes %u mode 0x%x generation %x } } "
            "ace { type %u flags %u access_mask %u } mask_matched %u",
            __entry->z_id, __entry->z_unlinked, __entry->z_atime_dirty,
@@ -132,7 +129,7 @@ DECLARE_EVENT_CLASS(zfs_ace_class,
            __entry->z_pflags, __entry->z_sync_cnt,
            __entry->z_sync_writes_cnt, __entry->z_async_writes_cnt,
            __entry->z_mode, __entry->z_is_sa, __entry->z_is_mapped,
-           __entry->z_is_ctldir, __entry->z_is_stale, __entry->i_uid,
+           __entry->z_is_ctldir, __entry->i_uid,
            __entry->i_gid, __entry->i_ino, __entry->i_nlink,
            __entry->i_size, __entry->i_blkbits,
            __entry->i_bytes, __entry->i_mode, __entry->i_generation,

diff --git a/include/os/linux/zfs/sys/zpl.h b/include/os/linux/zfs/sys/zpl.h
index 30d73db6b9e81ab819a10500b02fe4e881aa0d5b..83416d64744ce36ecd8e3cceae8b13cec3ae367b 100644 (file)
--- a/include/os/linux/zfs/sys/zpl.h
+++ b/include/os/linux/zfs/sys/zpl.h
@@ -45,7 +45,8 @@ extern const struct inode_operations zpl_inode_operations;
 extern const struct inode_operations zpl_dir_inode_operations;
 extern const struct inode_operations zpl_symlink_inode_operations;
 extern const struct inode_operations zpl_special_inode_operations;
-extern dentry_operations_t zpl_dentry_operations;
+
+/* zpl_file.c */
 extern const struct address_space_operations zpl_address_space_operations;
 extern const struct file_operations zpl_file_operations;
 extern const struct file_operations zpl_dir_file_operations;

diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index 7c906050bc4736c46b722cf7d9bc34c62d54a781..c8656b3f6162b7af96432929c6b349dc7aa91570 100644 (file)
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -190,7 +190,6 @@ typedef struct znode {
        boolean_t       z_is_sa;        /* are we native sa? */
        boolean_t       z_is_mapped;    /* are we mmap'ed */
        boolean_t       z_is_ctldir;    /* are we .zfs entry */
-       boolean_t       z_is_stale;     /* are we stale due to rollback? */
        boolean_t       z_suspended;    /* extra ref from a suspend? */
        uint_t          z_blksz;        /* block size in bytes */
        uint_t          z_seq;          /* modification sequence number */

diff --git a/module/os/linux/zfs/zfs_ctldir.c b/module/os/linux/zfs/zfs_ctldir.c
index 4ae0a65370e5b553d958bca809daf6fefe8b32ee..519f13212facdcabb34a66cc470f124909f7b32d 100644 (file)
--- a/module/os/linux/zfs/zfs_ctldir.c
+++ b/module/os/linux/zfs/zfs_ctldir.c
@@ -487,7 +487,6 @@ zfsctl_inode_alloc(zfsvfs_t *zfsvfs, uint64_t id,
        zp->z_is_sa = B_FALSE;
        zp->z_is_mapped = B_FALSE;
        zp->z_is_ctldir = B_TRUE;
-       zp->z_is_stale = B_FALSE;
        zp->z_sa_hdl = NULL;
        zp->z_blksz = 0;
        zp->z_seq = 0;

diff --git a/module/os/linux/zfs/zfs_vfsops.c b/module/os/linux/zfs/zfs_vfsops.c
index 7b682e49d84e75a725b365330471a4db6fe8e701..c921e587c75cafe52a66413ba45fc698925cb0f4 100644 (file)
--- a/module/os/linux/zfs/zfs_vfsops.c
+++ b/module/os/linux/zfs/zfs_vfsops.c
@@ -1522,7 +1522,6 @@ zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
        sb->s_op = &zpl_super_operations;
        sb->s_xattr = zpl_xattr_handlers;
        sb->s_export_op = &zpl_export_operations;
-       sb->s_d_op = &zpl_dentry_operations;
 
        /* Set features for file system. */
        zfs_set_fuid_feature(zfsvfs);
@@ -1881,8 +1880,8 @@ zfs_resume_fs(zfsvfs_t *zfsvfs, dsl_dataset_t *ds)
            zp = list_next(&zfsvfs->z_all_znodes, zp)) {
                err2 = zfs_rezget(zp);
                if (err2) {
+                       zpl_d_drop_aliases(ZTOI(zp));
                        remove_inode_hash(ZTOI(zp));
-                       zp->z_is_stale = B_TRUE;
                }
 
                /* see comment in zfs_suspend_fs() */

diff --git a/module/os/linux/zfs/zfs_znode.c b/module/os/linux/zfs/zfs_znode.c
index 9aeffba861504c0779cd0f84d151768b7a9ffab2..3ded79a30a6f2d2bea1707dc9a5330b6b021220c 100644 (file)
--- a/module/os/linux/zfs/zfs_znode.c
+++ b/module/os/linux/zfs/zfs_znode.c
@@ -552,7 +552,6 @@ zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz,
        zp->z_atime_dirty = B_FALSE;
        zp->z_is_mapped = B_FALSE;
        zp->z_is_ctldir = B_FALSE;
-       zp->z_is_stale = B_FALSE;
        zp->z_suspended = B_FALSE;
        zp->z_sa_hdl = NULL;
        zp->z_mapcnt = 0;

diff --git a/module/os/linux/zfs/zpl_inode.c b/module/os/linux/zfs/zpl_inode.c
index 8d073ff8cbd3bed8aae50ed7b735de29f5cd4874..9b702c535ea7a11515b651c8e2c400ee9cb7b364 100644 (file)
--- a/module/os/linux/zfs/zpl_inode.c
+++ b/module/os/linux/zfs/zpl_inode.c
@@ -728,46 +728,6 @@ out:
        return (error);
 }
 
-static int
-#ifdef HAVE_D_REVALIDATE_NAMEIDATA
-zpl_revalidate(struct dentry *dentry, struct nameidata *nd)
-{
-       unsigned int flags = (nd ? nd->flags : 0);
-#else
-zpl_revalidate(struct dentry *dentry, unsigned int flags)
-{
-#endif /* HAVE_D_REVALIDATE_NAMEIDATA */
-       /* CSTYLED */
-       zfsvfs_t *zfsvfs = dentry->d_sb->s_fs_info;
-       int error;
-
-       if (flags & LOOKUP_RCU)
-               return (-ECHILD);
-
-       /*
-        * After a rollback negative dentries created before the rollback
-        * time must be invalidated.  Otherwise they can obscure files which
-        * are only present in the rolled back dataset.
-        */
-       if (dentry->d_inode == NULL) {
-               spin_lock(&dentry->d_lock);
-               error = time_before(dentry->d_time, zfsvfs->z_rollback_time);
-               spin_unlock(&dentry->d_lock);
-
-               if (error)
-                       return (0);
-       }
-
-       /*
-        * The dentry may reference a stale inode if a mounted file system
-        * was rolled back to a point in time where the object didn't exist.
-        */
-       if (dentry->d_inode && ITOZ(dentry->d_inode)->z_is_stale)
-               return (0);
-
-       return (1);
-}
-
 const struct inode_operations zpl_inode_operations = {
        .setattr        = zpl_setattr,
        .getattr        = zpl_getattr,
@@ -856,7 +816,3 @@ const struct inode_operations zpl_special_inode_operations = {
        .get_acl        = zpl_get_acl,
 #endif /* CONFIG_FS_POSIX_ACL */
 };
-
-dentry_operations_t zpl_dentry_operations = {
-       .d_revalidate   = zpl_revalidate,
-};